Session Variables

The SET statement can modify one of the session configuration variables. These can also be queried via SHOW. By default, session variable values are set for the duration of the current session. CockroachDB supports setting session variables for the duration of a single transaction, using the LOCAL keyword.

Supported variables

Variable name	Description	Initial value	Modify with `SET`?	View with `SHOW`?
	`application_name`	The current application name for statistics collection.	Empty string, or `cockroach` for sessions from the built-in SQL client.	Yes	Yes
	`autocommit_before_ddl`	When the `autocommit_before_ddl` session setting is set to `on`, any schema change statement that is sent during an explicit transaction will cause the transaction to commit before executing the schema change.	`off`	Yes	Yes
	`bytea_output`	The mode for conversions from `STRING` to `BYTES`.	hex	Yes	Yes
	`client_min_messages`	The severity level of notices displayed in the SQL shell. Accepted values include `debug5`, `debug4`, `debug3`, `debug2`, `debug1`, `log`, `notice`, `warning`, and `error`.	`notice`	Yes	Yes
	`copy_from_atomic_enabled`	If set to `on`, `COPY FROM` statements are committed atomically, matching PostgreSQL behavior. If set to `off`, `COPY FROM` statements are segmented into batches of 100 rows unless issued within an explicit transaction, matching the CockroachDB behavior in versions prior to v22.2.	`on`	Yes	Yes
	`copy_transaction_quality_of_service`	The default quality of service for `COPY` statements in the current session. The supported options are `regular`, `critical`, and `background`. See Set quality of service level.	`background`	Yes	Yes
	`cost_scans_with_default_col_size`	Whether to prevent the optimizer from considering column size when costing plans.	`false`	Yes	Yes
	`crdb_version`	The version of CockroachDB.	`CockroachDB OSS version`	No	Yes
	`database`	The current database.	Database in connection string, or empty if not specified.	Yes	Yes
	`datestyle`	The input string format for `DATE` and `TIMESTAMP` values. Accepted values include `ISO,MDY`, `ISO,DMY`, and `ISO,YMD`.	The value set by the `sql.defaults.datestyle` cluster setting (`ISO,MDY`, by default).	Yes	Yes
	`default_int_size`	The size, in bytes, of an `INT` type.	`8`	Yes	Yes
	`default_text_search_config`	The dictionary used to normalize tokens and eliminate stop words when calling a full-text search function without a configuration parameter. See Full-Text Search.	`english`	Yes	Yes
	`default_transaction_isolation`	The isolation level at which transactions in the session execute (`SERIALIZABLE` or `READ COMMITTED`). See Isolation levels.	`SERIALIZABLE`	Yes	Yes
	`default_transaction_priority`	The default transaction priority for the current session. The supported options are `low`, `normal`, and `high`.	`normal`	Yes	Yes
	`default_transaction_quality_of_service`	The default transaction quality of service for the current session. The supported options are `regular`, `critical`, and `background`. See Set quality of service level.	`regular`	Yes	Yes
	`default_transaction_read_only`	The default transaction access mode for the current session. If set to `on`, only read operations are allowed in transactions in the current session; if set to `off`, both read and write operations are allowed. See `SET TRANSACTION` for more details.	`off`	Yes	Yes
	`default_transaction_use_follower_reads`	If set to on, all read-only transactions use `AS OF SYSTEM TIME follower_read_timestamp()` to allow the transaction to use follower reads. If set to `off`, read-only transactions will only use follower reads if an `AS OF SYSTEM TIME` clause is specified in the statement, with an interval of at least 4.8 seconds.	`off`	Yes	Yes
	`disable_changefeed_replication`	When `true`, changefeeds will not emit messages for any changes (e.g., `INSERT`, `UPDATE`) issued to watched tables during that session.	`false`	Yes	Yes
	`disallow_full_table_scans`	If set to `on`, queries on “large” tables with a row count greater than `large_full_scan_rows` will not use full table or index scans. If no other query plan is possible, queries will return an error message. This setting does not apply to internal queries, which may plan full table or index scans without checking the session variable.	`off`	Yes	Yes	`distsql`	The query distribution mode for the session. By default, CockroachDB determines which queries are faster to execute if distributed across multiple nodes, and all other queries are run through the gateway node.	`auto`	Yes	Yes
	`enable_auto_rehoming`	When enabled, the home regions of rows in `REGIONAL BY ROW` tables are automatically set to the region of the gateway node from which any `UPDATE` or `UPSERT` statements that operate on those rows originate.	`off`	Yes	Yes
	`enable_create_stats_using_extremes`	If `on`, allows manual creation of partial statistics using the `CREATE STATISTICS ... USING EXTREMES` syntax.	`off`	Yes	Yes
	`enable_durable_locking_for_serializable`	Indicates whether CockroachDB replicates `FOR UPDATE` and `FOR SHARE` locks via Raft, allowing locks to be preserved when leases are transferred. Note that replicating `FOR UPDATE` and `FOR SHARE` locks will add latency to those statements. This setting only affects `SERIALIZABLE` transactions and matches the default `READ COMMITTED` behavior when enabled.	`off`	Yes	Yes
	`enable_experimental_alter_column_type_general`	If `on`, it is possible to alter column data types.	`off`	Yes	Yes
	`enable_implicit_fk_locking_for_serializable`	Indicates whether CockroachDB uses shared locks to perform foreign key checks. To take effect, the `enable_shared_locking_for_serializable` setting must also be enabled. This setting only affects `SERIALIZABLE` transactions and matches the default `READ COMMITTED` behavior when enabled.	`off`	Yes	Yes
	`enable_implicit_select_for_update`	Indicates whether `UPDATE` and `UPSERT` statements acquire locks using the `FOR UPDATE` locking mode during their initial row scan, which improves performance for contended workloads. For more information about how `FOR UPDATE` locking works, see the documentation for `SELECT FOR UPDATE`.	`on`	Yes	Yes
	`enable_implicit_transaction_for_batch_statements`	Indicates whether multiple statements in a single query (a “batch statement”) will all run in the same implicit transaction, which matches the PostgreSQL wire protocol.	`on`	Yes	Yes
	`enable_insert_fast_path`	Indicates whether CockroachDB will use a specialized execution operator for inserting into a table. We recommend leaving this setting `on`.	`on`	Yes	Yes
	`enable_shared_locking_for_serializable`	Indicates whether shared locks are enabled for `SERIALIZABLE` transactions. When `off`, `SELECT` statements using `FOR SHARE` are still permitted under `SERIALIZABLE` isolation, but silently do not lock.	`off`	Yes	Yes
	`enable_super_regions`	When enabled, you can define a super region: a set of database regions on a multi-region cluster such that your schema objects will have all of their replicas stored only in regions that are members of the super region.	`off`	Yes	Yes
	`enable_zigzag_join`	Indicates whether the cost-based optimizer will plan certain queries using a zigzag merge join algorithm, which searches for the desired intersection by jumping back and forth between the indexes based on the fact that after constraining indexes, they share an ordering.	`on`	Yes	Yes
	`enforce_home_region`	If set to `on`, queries return an error and in some cases a suggested resolution if they cannot run entirely in their home region. This can occur if a query has no home region (for example, if it reads from different home regions in a regional by row table) or a query’s home region differs from the gateway region. Note that only tables with `ZONE` survivability can be scanned without error when this is enabled. For more information about home regions, see Table localities. This feature is in preview. It is subject to change.	`off`	Yes	Yes
	`enforce_home_region_follower_reads_enabled`	If `on` while the `enforce_home_region` setting is `on`, allows `enforce_home_region` to perform `AS OF SYSTEM TIME` follower reads to detect and report a query’s home region, if any. This feature is in preview. It is subject to change.	`off`	Yes	Yes
	`expect_and_ignore_not_visible_columns_in_copy`	If `on`, `COPY FROM` with no column specifiers will assume that hidden columns are in the copy data, but will ignore them when applying `COPY FROM`.	`off`	Yes	Yes
	`extra_float_digits`	The number of digits displayed for floating-point values. Only values between `-15` and `3` are supported.	`0`	Yes	Yes
	`force_savepoint_restart`	When set to `true`, allows the `SAVEPOINT` statement to accept any name for a savepoint.	`off`	Yes	Yes
	`foreign_key_cascades_limit`	Limits the number of cascading operations that run as part of a single query.	`10000`	Yes	Yes
	`idle_in_session_timeout`	Automatically terminates sessions that idle past the specified threshold. When set to `0`, the session will not timeout.	The value set by the `sql.defaults.idle_in_session_timeout` cluster setting (`0s`, by default).	Yes	Yes
	`idle_in_transaction_session_timeout`	Automatically terminates sessions that are idle in a transaction past the specified threshold. When set to `0`, the session will not timeout.	The value set by the `sql.defaults.idle_in_transaction_session_timeout` cluster setting (0s, by default).	Yes	Yes
	`index_recommendations_enabled`	If `true`, display recommendations to create indexes required to eliminate full table scans. For more details, see Default statement plans.	`true`	Yes	Yes
	`inject_retry_errors_enabled`	If `true`, any statement executed inside of an explicit transaction (with the exception of `SET` statements) will return a transaction retry error. If the client retries the transaction using the special `cockroach_restart SAVEPOINT` name, after the 3rd retry error, the transaction will proceed as normal. Otherwise, the errors will continue until `inject_retry_errors_enabled` is set to `false`. For more details, see Test transaction retry logic.	`false`	Yes	Yes
	`intervalstyle`	The input string format for `INTERVAL` values. Accepted values include `postgres`, `iso_8601`, and `sql_standard`.	The value set by the `sql.defaults.intervalstyle` cluster setting (`postgres`, by default).	Yes	Yes
	`is_superuser`	If `on` or `true`, the current user is a member of the `admin` role.	User-dependent	No	Yes
	`large_full_scan_rows`	Determines which tables are considered “large” such that `disallow_full_table_scans` rejects full table or index scans of “large” tables. The default value is `1000`. To reject all full table or index scans, set to `0`.	User-dependent	No	Yes
	`legacy_varchar_typing`	New in v24.2.7: If `on`, type checking and overload resolution for `VARCHAR` types ignore overloads that cause errors, allowing comparisons between `VARCHAR` and non-`STRING`-like placeholder values to execute successfully. If `off`, type checking of these comparisons is more strict and must be handled with explicit type casts.	`on`	Yes	Yes
`locality`	The location of the node. </br>For more information, see Locality.	Node-dependent	No	Yes
	`lock_timeout`	The amount of time a query can spend acquiring or waiting for a single row-level lock. In CockroachDB, unlike in PostgreSQL, non-locking reads wait for conflicting locks to be released. As a result, the `lock_timeout` configuration applies to writes, and to locking and non-locking reads in read-write and read-only transactions. If `lock_timeout = 0`, queries do not timeout due to lock acquisitions.	The value set by the `sql.defaults.lock_timeout` cluster setting (`0`, by default)	Yes	Yes
	`multiple_active_portals_enabled`	Whether to enable the multiple active portals pgwire feature.	`false`	Yes	Yes
	`node_id`	The ID of the node currently connected to. This variable is particularly useful for verifying load balanced connections.	Node-dependent	No	Yes
	`null_ordered_last`	Set the default ordering of `NULL`s. The default order is `NULL`s first for ascending order and `NULL`s last for descending order.	`false`	Yes	Yes
	`optimizer_merge_joins_enabled`	If `on`, the optimizer will explore query plans with merge joins.	`on`	Yes	Yes
	`optimizer_push_offset_into_index_join`	If `on`, the optimizer will attempt to push offset expressions into index join expressions to produce more efficient query plans.	`on`	Yes	Yes
	`optimizer_use_forecasts`	If `on`, the optimizer uses forecasted statistics for query planning.	`on`	Yes	Yes
	`optimizer_use_histograms`	If `on`, the optimizer uses collected histograms for cardinality estimation.	`on`	No	Yes
	`optimizer_use_improved_multi_column_selectivity_estimate`	If `on`, the optimizer uses an improved selectivity estimate for multi-column predicates.	`on`	Yes	Yes
	`optimizer_use_improved_zigzag_join_costing`	If `on`, the cost of zigzag joins is updated so they will be never be chosen over scans unless they produce fewer rows. To take effect, the `enable_zigzag_join` setting must also be enabled.	`on`	Yes	Yes
	`optimizer_use_lock_op_for_serializable`	If `on`, the optimizer uses a `Lock` operator to construct query plans for `SELECT` statements using the `FOR UPDATE` and `FOR SHARE` clauses. This setting only affects `SERIALIZABLE` transactions. `READ COMMITTED` transactions are evaluated with the `Lock` operator regardless of the setting.	`off`	Yes	Yes
	`optimizer_use_multicol_stats`	If `on`, the optimizer uses collected multi-column statistics for cardinality estimation.	`on`	No	Yes
	`optimizer_use_not_visible_indexes`	If `on`, the optimizer uses not visible indexes for planning.	`off`	No	Yes
	`optimizer_use_virtual_computed_column_stats`	If `on`, the optimizer uses table statistics on virtual computed columns.	`on`	Yes	Yes
	`plan_cache_mode`	The type of plan that is cached in the query plan cache: `auto`, `force_generic_plan`, or `force_custom_plan`. For more information, refer to Query plan type.	`force_custom_plan`	Yes	Yes
	`plpgsql_use_strict_into`	If `on`, PL/pgSQL `SELECT ... INTO` and `RETURNING ... INTO` statements behave as though the `STRICT` option is specified. This causes the SQL statement to error if it does not return exactly one row.	`off`	Yes	Yes
	`pg_trgm.similarity_threshold`	The threshold above which a `%` string comparison returns `true`. The value must be between `0` and `1`. For more information, see Trigram Indexes.	`0.3`	Yes	Yes
	`prefer_lookup_joins_for_fks`	If `on`, the optimizer prefers `lookup joins` to `merge joins` when performing `foreign key` checks.	`off`	Yes	Yes
	`reorder_joins_limit`	Maximum number of joins that the optimizer will attempt to reorder when searching for an optimal query execution plan. For more information, see Join reordering.	`8`	Yes	Yes
	`require_explicit_primary_keys`	If `on`, CockroachDB throws an error for all tables created without an explicit primary key defined.	`off`	Yes	Yes
	`search_path`	A list of schemas that will be searched to resolve unqualified table or function names. For more details, see SQL name resolution.	`public`	Yes	Yes
	`serial_normalization`	Specifies the default handling of `SERIAL` in table definitions. Valid options include `'rowid'`, `'virtual_sequence'`, `sql_sequence`, `sql_sequence_cached`, and `unordered_rowid`. If set to `'virtual_sequence'`, the `SERIAL` type auto-creates a sequence for better compatibility with Hibernate sequences. If set to `sql_sequence_cached`, you can use the `sql.defaults.serial_sequences_cache_size` cluster setting to control the number of values to cache in a user’s session, with a default of 256. If set to `unordered_rowid`, the `SERIAL` type generates a globally unique 64-bit integer (a combination of the insert timestamp and the ID of the node executing the statement) that does not have unique ordering.	`'rowid'`	Yes	Yes
	`server_version`	The version of PostgreSQL that CockroachDB emulates.	Version-dependent	No	Yes
	`server_version_num`	The version of PostgreSQL that CockroachDB emulates.	Version-dependent	Yes	Yes
	`session_id`	The ID of the current session.	Session-dependent	No	Yes
	`session_user`	The user connected for the current session.	User in connection string	No	Yes
	`sql_safe_updates`	If `true`, the following potentially unsafe SQL statements are disallowed: `DROP DATABASE` of a non-empty database and all dependent objects; `DELETE` and `UPDATE` without a `WHERE` clause, unless a `LIMIT` clause is included; `SELECT ... FOR UPDATE` and `SELECT ... FOR SHARE` without a `WHERE` or `LIMIT` clause; and `ALTER TABLE ... DROP COLUMN`. For more details, refer to Allow potentially unsafe SQL statements.	`true` for interactive sessions from the built-in SQL client, `false` for sessions from other clients	Yes	Yes
	`statement_timeout`	The amount of time a statement can run before being stopped. This value can be an `int` (e.g., `10`) and will be interpreted as milliseconds. It can also be an interval or string argument, where the string can be parsed as a valid interval (e.g., `'4s'`). A value of `0` turns it off.	The value set by the `sql.defaults.statement_timeout` cluster setting (`0s`, by default).	Yes	Yes
	`stub_catalog_tables`	If `off`, querying an unimplemented, empty `pg_catalog` table will result in an error, as is the case in v20.2 and earlier. If `on`, querying an unimplemented, empty `pg_catalog` table simply returns no rows.	`on`	Yes	Yes
	`timezone`	The default time zone for the current session.	`UTC`	Yes	Yes
	`tracing`	The trace recording state.	`off`	Yes	Yes
	`transaction_isolation`	The isolation level at which the transaction executes (`SERIALIZABLE` or `READ COMMITTED`). See Isolation levels.	`SERIALIZABLE`	Yes	Yes
	`transaction_priority`	The priority of the current transaction. See Transactions: Transaction priorities for more details. This session variable was called transaction priority (with a space) in CockroachDB 1.x. It has been renamed for compatibility with PostgreSQL.	`NORMAL`	Yes	Yes
	`transaction_read_only`	The access mode of the current transaction. See `SET TRANSACTION` for more details.	`off`	Yes	Yes
	`transaction_rows_read_err`	The limit for the number of rows read by a SQL transaction. If this value is exceeded the transaction will fail (or the event will be logged to `SQL_INTERNAL_PERF` for internal transactions).	`0`	Yes	Yes
	`transaction_rows_read_log`	The threshold for the number of rows read by a SQL transaction. If this value is exceeded, the event will be logged to `SQL_PERF` (or `SQL_INTERNAL_PERF` for internal transactions).	`0`	Yes	Yes
	`transaction_rows_written_err`	The limit for the number of rows written by a SQL transaction. If this value is exceeded the transaction will fail (or the event will be logged to `SQL_INTERNAL_PERF` for internal transactions).	`0`	Yes	Yes
	`transaction_rows_written_log`	The threshold for the number of rows written by a SQL transaction. If this value is exceeded, the event will be logged to `SQL_PERF` (or `SQL_INTERNAL_PERF` for internal transactions).	`0`	Yes	Yes
	`transaction_status`	The state of the current transaction. See Transactions for more details.	`NoTxn`	No	Yes
	`transaction_timeout`	Aborts an explicit transaction when it runs longer than the configured duration. Stored in milliseconds; can be expressed in milliseconds or as an `INTERVAL`.	`0`	Yes	Yes
	`troubleshooting_mode_enabled`	When enabled, avoid performing additional work on queries, such as collecting and emitting telemetry data. This session variable is particularly useful when the cluster is experiencing issues, unavailability, or failure.	`off`	Yes	Yes
	`use_declarative_schema_changer`	Whether to use the declarative schema changer for supported statements.	`on`	Yes	Yes
	`vectorize`	The vectorized execution engine mode. Options include `on` and `off`. For more details, see Configure vectorized execution for CockroachDB.	`on`	Yes	Yes
	`virtual_cluster_name`	The name of the virtual cluster that the SQL client is connected to.	Session-dependent	No	Yes

The following session variables are exposed only for backwards compatibility with earlier CockroachDB releases and have no impact on how CockroachDB runs:

Initial value	Modify with `SET`?	View with `SHOW`?
`backslash_quote`	`safe_encoding`	No	Yes
`client_encoding`	`UTF8`	No	Yes
`default_tablespace`		No	Yes
`enable_drop_enum_value`	`off`	Yes	Yes
`enable_seqscan`	`on`	Yes	Yes
`escape_string_warning`	`on`	No	Yes
`experimental_enable_hash_sharded_indexes`	`off`	Yes	Yes
`integer_datetimes`	`on`	No	Yes
`max_identifier_length`	`128`	No	Yes
`max_index_keys`	`32`	No	Yes
`row_security`	`off`	No	Yes
`standard_conforming_strings`	`on`	No	Yes
`server_encoding`	`UTF8`	Yes	Yes
`synchronize_seqscans`	`on`	No	Yes
`synchronous_commit`	`on`	Yes	Yes

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Supported variables

See also

​Supported variables

​See also

Supported variables

See also